The invention relates to nozzle assemblies for hydraulic jet looms, and more particularly to nozzle assemblies of this type wherein a weft-propelling fluid injected radially into the assembly via a radial opening in the outer nozzle housing is loaded into a pressure chamber in intermittent communication with a weft-receiving central region of the nozzle.
In existing nozzle assemblies of this type, it is customary to locate the radial opening in the outer nozzle housing so that the inner end of such opening is in direct communication with a pressure chamber, which is bounded on one side by the front flange of the nozzle member proper. As a result, the weft-propelling liquid introduced into the assembly via the radial opening flows directly into the pressure chamber.
A disadvantage of such arrangement is that the direct loading of the pressure chamber in this manner causes liquid to flow around two sides of a tubular portion of the nozzle element extending rearwardly from the front flange, leading to perturbations in the rate of filling of the chamber and thereby to a turbulent flow of the pressure pulses of such fluid between the inlet port of the assembly and the pressure chamber. Such turbulent flow has been found to adversely affect the properties of the liquid flowing out of the nozzle during the weft insertion operation, thereby degrading the weft insertion operation particularly when weaving at high speeds or with yarns having high denier numbers.